From 36b5248618f6efe06a633882baead089df042ca5 Mon Sep 17 00:00:00 2001
From: Brandon Blaylock <brandon@null.pub>
Date: Sat, 10 Apr 2021 13:20:24 -0700
Subject: [PATCH] feat: io tests complete

---
 derivations.ts     | 28 +++++++++----
 io.ts              | 13 ++----
 testing/io.test.ts | 99 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 124 insertions(+), 16 deletions(-)
 create mode 100644 testing/io.test.ts

diff --git a/derivations.ts b/derivations.ts
index c01a502..3620bcd 100644
--- a/derivations.ts
+++ b/derivations.ts
@@ -36,20 +36,34 @@ export const createDo = <URI extends URIS>(
     name: N,
   ): (<A, B, C, D>(
     ta: Kind<URI, [A, B, C, D]>,
-    // deno-lint-ignore no-explicit-any
   ) => Kind<URI, [{ [K in N]: A }, B, C, D]>) =>
+    // deno-lint-ignore no-explicit-any
     M.map((a: any): any => ({ [name]: a })),
   bind: <N extends string, A, I, B, C, D>(
     name: Exclude<N, keyof A>,
     fati: (a: A) => Kind<URI, [I, B, C, D]>,
-  ): ((
-    ma: Kind<URI, [A, B, C, D]>,
-  ) => Kind<
-    URI,
-    [{ readonly [K in keyof A | N]: K extends keyof A ? A[K] : I }, B, C, D]
-  > // deno-lint-ignore no-explicit-any
+  ): (
+    (
+      ma: Kind<URI, [A, B, C, D]>,
+    ) => Kind<
+      URI,
+      [{ readonly [K in keyof A | N]: K extends keyof A ? A[K] : I }, B, C, D]
+    >
   ) =>
+    // deno-lint-ignore no-explicit-any
     M.chain((a: any): any =>
+      // deno-lint-ignore no-explicit-any
       pipe(a, fati, M.map((b: any): any => ({ ...a, [name]: b })))
     ),
 });
+
+/*******************************************************************************
+ * Derive getSemigroup from Apply
+ ******************************************************************************/
+
+export const createApplySemigroup = <URI extends URIS>(A: TC.Apply<URI>) =>
+  <A, B = never, C = never, D = never>(
+    S: TC.Semigroup<A>,
+  ): TC.Semigroup<Kind<URI, [A, B, C, D]>> => ({
+    concat: (a) => A.ap(pipe(a, A.map(S.concat))),
+  });
diff --git a/io.ts b/io.ts
index f74ecc1..32bcb70 100644
--- a/io.ts
+++ b/io.ts
@@ -3,7 +3,7 @@ import type * as TC from "./type_classes.ts";
 
 import { createSequenceStruct, createSequenceTuple } from "./sequence.ts";
 import { apply, constant, flow, pipe } from "./fns.ts";
-import { createDo } from "./derivations.ts";
+import { createApplySemigroup, createDo } from "./derivations.ts";
 
 /*******************************************************************************
  * Types
@@ -59,11 +59,6 @@ export const Monad: TC.Monad<URI> = {
   chain: Chain.chain,
 };
 
-export const Alt: TC.Alt<URI> = {
-  alt: constant,
-  map: Monad.map,
-};
-
 export const Extends: TC.Extend<URI> = {
   map: Monad.map,
   extend: (ftab) => (ta) => () => ftab(ta),
@@ -83,9 +78,7 @@ export const Traversable: TC.Traversable<URI> = {
  * Module Getters
  ******************************************************************************/
 
-export const getSemigroup = <A>(S: TC.Semigroup<A>): TC.Semigroup<IO<A>> => ({
-  concat: (x) => (y) => () => S.concat(x())(y()),
-});
+export const getSemigroup = createApplySemigroup(Apply);
 
 export const getMonoid = <A>(M: TC.Monoid<A>): TC.Monoid<IO<A>> => ({
   ...getSemigroup(M),
@@ -100,6 +93,8 @@ export const { of, ap, map, join, chain } = Monad;
 
 export const { reduce, traverse } = Traversable;
 
+export const { extend } = Extends;
+
 /*******************************************************************************
  * Sequenec
  ******************************************************************************/
diff --git a/testing/io.test.ts b/testing/io.test.ts
new file mode 100644
index 0000000..aeca676
--- /dev/null
+++ b/testing/io.test.ts
@@ -0,0 +1,99 @@
+import { assertEquals } from "https://deno.land/std/testing/asserts.ts";
+
+import * as AS from "./assert.ts";
+
+import * as I from "../io.ts";
+import * as O from "../option.ts";
+import { semigroupSum } from "../semigroup.ts";
+import { monoidSum } from "../monoid.ts";
+import { pipe } from "../fns.ts";
+
+// deno-lint-ignore no-explicit-any
+const assertEqualsIO = (a: I.IO<any>, b: I.IO<any>) => assertEquals(a(), b());
+
+Deno.test("IO getSemigroup", () => {
+  const Semigroup = I.getSemigroup(semigroupSum);
+  const concat = Semigroup.concat(I.of(1));
+
+  assertEqualsIO(concat(I.of(1)), I.of(2));
+});
+
+Deno.test("IO getMonoid", () => {
+  const Monoid = I.getMonoid(monoidSum);
+  const empty = Monoid.empty();
+
+  assertEqualsIO(empty, I.of(0));
+});
+
+Deno.test("IO of", () => {
+  assertEqualsIO(I.of(1), I.of(1));
+});
+
+Deno.test("IO ap", () => {
+  const ap = I.ap(I.of(AS.add));
+  assertEqualsIO(ap(I.of(1)), I.of(2));
+});
+
+Deno.test("IO map", () => {
+  const map = I.map(AS.add);
+  assertEqualsIO(map(I.of(1)), I.of(2));
+});
+
+Deno.test("IO join", () => {
+  assertEqualsIO(I.join(I.of(I.of(1))), I.of(1));
+});
+
+Deno.test("IO chain", () => {
+  const chain = I.chain((n: number) => I.of(n + 1));
+  assertEqualsIO(chain(I.of(1)), I.of(2));
+});
+
+Deno.test("IO reduce", () => {
+  const reduce = I.reduce((acc: number, cur: number) => acc + cur, 0);
+  assertEquals(reduce(I.of(1)), 1);
+});
+
+Deno.test("IO traverse", () => {
+  const fold = O.fold((n: I.IO<number>) => n(), () => -1);
+  const t0 = I.traverse(O.Applicative);
+  const t1 = t0((n: number) => n === 0 ? O.none : O.some(n));
+  const t2 = fold(t1(I.of(0)));
+  const t3 = fold(t1(I.of(1)));
+
+  assertEquals(t2, -1);
+  assertEquals(t3, 1);
+});
+
+Deno.test("IO extend", () => {
+  const extend = I.extend((ta: I.IO<number>) => ta() + 1);
+  assertEqualsIO(extend(I.of(1)), I.of(2));
+});
+
+Deno.test("IO sequenceTuple", () => {
+  const r1 = I.sequenceTuple(I.of(1), I.of("Hello World"));
+  assertEqualsIO(r1, I.of([1, "Hello World"]));
+});
+
+Deno.test("IO sequenceStruct", () => {
+  const r1 = I.sequenceStruct({ a: I.of(1), b: I.of("Hello World") });
+  assertEqualsIO(r1, I.of({ a: 1, b: "Hello World" }));
+});
+
+Deno.test("IO Do, bind, bindTo", () => {
+  assertEqualsIO(
+    pipe(
+      I.Do(),
+      I.bind("one", () => I.of(1)),
+      I.bind("two", ({ one }) => I.of(one + one)),
+      I.map(({ one, two }) => one + two),
+    ),
+    I.of(3),
+  );
+  assertEqualsIO(
+    pipe(
+      I.of(1),
+      I.bindTo("one"),
+    ),
+    I.of({ one: 1 }),
+  );
+});